Method to clean SnO2 film from chamber

Abstract

A method for cleaning SnO2 residue from a processing chamber is provided as one embodiment. The method embodiment includes introducing hydrocarbon and hydrogen gas at a ratio of 1%-60% into a plasma processing system. The SnO2 residue is etched from surfaces the processing chamber using plasma generated by a plasma source, which produces SnH4 gas. The SnH4 gas reacts with the hydrocarbon gas to produce an organotin compound that is volatilizable. The method further provides for evacuating the processing chamber of the organotin compound. The introduction of the hydrocarbon gas along with the hydrogen gas at the ratio of 1%-60% reduces a rate of SnH4 gas decomposition into Sn powder.

What is claimed is: 
     
       1. A method for cleaning SnO 2  residue from a processing chamber, comprising:
 introducing hydrocarbon gas and hydrogen gas into a plasma processing system; 
 etching the SnO 2  residue in crystalline form from surfaces of the processing chamber using plasma generated by a plasma source of the plasma processing system, said etching the SnO 2  residue with the hydrogen gas produces SnH 4  gas, the SnH 4  gas reacts with the hydrocarbon gas to produce an organotin compound that is volatilizable, wherein said production of the organotin compound from said SnH 4  gas reduces an amount of SnH 4  gas available to be decomposed into Sn powder; and 
 evacuating the processing chamber of the organotin compound, wherein a ratio of a flow of said hydrocarbon gas to said hydrogen gas is at least 1% hydrocarbon gas to hydrogen gas and less than 60% hydrocarbon gas to hydrogen gas. 
 
     
     
       2. The method of  claim 1 , wherein the hydrocarbon gas is configured to provide a reaction pathway for SnH 4  gas to produce the organotin compound that is more kinetically favorable than the SnH 4  gas decomposition into Sn powder, wherein producing the organotin compound enables suction of the organotin compound out of the processing chamber to prevent Sn powder from being deposited on the surfaces of the processing chamber during said etching the SnO 2  residue. 
     
     
       3. The method of  claim 1 , wherein a temperature of the processing chamber is maintained at between 65° C. and 300° C. for enabling volatilization of the organotin compound and suction of the organotin compound as volatilized out of the processing chamber. 
     
     
       4. The method of  claim 1 , wherein a pressure of the processing chamber is maintained at between 0.1 Torr to 10 Torr for enabling reaction of SnH 4  with the hydrocarbon gas to produce the organotin compound. 
     
     
       5. The method of  claim 1 , wherein the ratio of at least 1% hydrocarbon gas to hydrogen gas enables the hydrocarbon gas to react with the SnH 4  gas to reduce available SnH 4  gas for decomposition into said Sn powder, and wherein the ratio of less than 60% hydrocarbon gas to hydrogen gas reduces formation of carbonaceous polymers and their deposition on the surfaces of the processing chamber. 
     
     
       6. The method of  claim 1 , wherein the hydrocarbon gas and the hydrogen gas are introduced into the processing chamber for generating the plasma by a capacitively coupled plasma (CCP) source of the processing chamber. 
     
     
       7. The method of  claim 1 , wherein the hydrocarbon gas and the hydrogen gas are introduced into an inductively coupled plasma (ICP) source remote to the processing chamber for generating plasma and radicals there generated are fed into the processing chamber for said etching. 
     
     
       8. The method of  claim 1 , wherein the hydrocarbon gas and the hydrogen gas are introduced into the processing chamber for generating plasma by a CCP source and into an ICP source for generating plasma by the ICP source, wherein radicals generated by the CCP source and the ICP source are used for said etching. 
     
     
       9. The method of  claim 1 , wherein the hydrocarbon gas is introduced into the processing chamber for generating plasma by a CCP source and radicals generated by the CCP source react with the SnH 4  gas to produce the organotin compound, and wherein the hydrogen gas is introduced into an ICP source remote from the processing chamber for generating plasma and radicals generated by the ICP source are transported to the processing chamber for said etching the SnO 2  residue. 
     
     
       10. The method of  claim 1 , wherein the hydrocarbon gas and the hydrogen gas are introduced into the processing chamber, the method further comprising:
 introducing argon gas or helium gas into an ICP source for generating plasma, the plasma produces radicals; and 
 transporting the radicals into the processing chamber for ionization of the hydrocarbon gas and the hydrogen gas for said etching the SnO 2  residue. 
 
     
     
       11. The method of  claim 1 , wherein the hydrocarbon gas is selected from the group consisting of CH 4 , CH 3 OH, C 2 H 5 OH, HCOOH, or a mixture of NH 3 +CH 4 . 
     
     
       12. A method for patterning an SnO 2  layer while reducing Sn powder formation on surfaces of a processing chamber of a plasma processing system, comprising:
 depositing a layer of SnO 2  in a crystalline form on a substrate and applying an etch mask to the layer of SnO 2 ; 
 introducing hydrocarbon gas and hydrogen gas into the plasma processing system; 
 etching the layer of SnO 2  where exposed by the etch mask using plasma generated by a plasma source, the etching the layer of SnO 2  produces SnH 4  gas, the SnH 4  gas reacts with the hydrocarbon gas to produce an organotin compound that is volatilizable, wherein said production of the organotin compound from said SnH 4  gas reduces an amount of SnH 4  gas available to be decomposed into Sn powder; and 
 evacuating the processing chamber of the organotin compound, wherein a ratio of a flow of said hydrocarbon gas to said hydrogen gas is at least 1% hydrocarbon gas to hydrogen gas and less than 60% hydrocarbon gas to hydrogen gas. 
 
     
     
       13. The method of  claim 12 , wherein the hydrocarbon gas is configured to provide a reaction pathway for SnH 4  gas to produce the organotin compound that is more kinetically favorable than the SnH 4  gas decomposition into Sn powder, wherein producing the organotin compound enables suction of the organotin compound out of the processing chamber to prevent tin powder from be deposited on the surfaces of the processing chamber during said etching the layer of SnO 2 . 
     
     
       14. The method of  claim 12 , wherein the ratio of at least 1% hydrocarbon gas to hydrogen gas enables the hydrocarbon gas to react with the SnH 4  gas to reduce available SnH 4  gas for decomposition into said Sn powder, and wherein the ratio of less than 60% hydrocarbon gas to hydrogen gas reduces formation of carbonaceous polymers and their deposition on the surfaces of the processing chamber. 
     
     
       15. The method of  claim 12 , wherein the hydrocarbon gas is selected from the group consisting of CH 4 , CH 3 OH, C 2 H 5 OH, HCOOH, or a mixture of NH 3 +CH 4 .